US10633730B2 - Material for cold-rolled stainless steel sheet - Google Patents

Material for cold-rolled stainless steel sheet Download PDF

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US10633730B2
US10633730B2 US15/508,665 US201515508665A US10633730B2 US 10633730 B2 US10633730 B2 US 10633730B2 US 201515508665 A US201515508665 A US 201515508665A US 10633730 B2 US10633730 B2 US 10633730B2
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sheet
cold
rolled
steel sheet
phase
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US20170275744A1 (en
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Ayako Ta
Yukihiro Matsubara
Yukio Kimura
Masataka Yoshino
Keisuke Nakazono
Sumio Kaiho
Saiichi Murata
Nobukazu Kitagawa
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JFE Steel Corp
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JFE Steel Corp
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    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C—CHEMISTRY; METALLURGY
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    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/54—Ferrous alloys, e.g. steel alloys containing chromium with nickel with boron
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    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
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    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
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    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
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    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
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    • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
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    • C21D2211/00—Microstructure comprising significant phases
    • C21D2211/005—Ferrite
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    • C21D2211/00—Microstructure comprising significant phases
    • C21D2211/008—Martensite
    • C—CHEMISTRY; METALLURGY
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    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
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Definitions

  • the present invention relates to a material for a cold-rolled stainless steel sheet, the material being suitable for manufacturing a cold-rolled ferritic stainless steel sheet which is excellent in terms of surface appearance quality and which has sufficient formability.
  • Ferritic stainless steel which is economical and excellent in terms of corrosion resistance, is used in various applications such as building materials, transportation instruments, home electrical appliances, kitchen equipment, and automobile parts, and the range of its application has been expanding in recent years. Of these applications, in applications in which surface appearance is important such as interior construction materials, bodies and doors of home electrical appliances, kitchen equipment, and molding for automobiles, good surface appearance is particularly emphasized.
  • Ridging is a defect unique to ferritic stainless steel and generated as irregularities extending in the rolling direction. Surface roughening is caused by undulation of coarse crystal grains. Ridging or surface roughening generated in a forming work process needs to be removed by polishing, which results in a considerable increase in the manufacturing load and manufacturing costs.
  • Patent Literature 1 discloses a ferritic stainless steel sheet having less planar anisotropy, being excellent in terms of ridging resistance and surface roughening resistance, and being characterized by subjecting steel containing, by mass %, C: 0.005% to 0.100%, Si: 0.01% to 2.00%, Mn: 0.01% to 2.00%, P: less than 0.040%, S: 0.03% or less, Cr: 10% to 22%, Al: 0.0005% to 0.2000%, and N: 0.005% to 0.080% to, as a heat treatment process after a hot rolling process, preliminary annealing and subsequently to main annealing, or to soaking treatment and further to partial transformation heat treatment at a high temperature of 900° C.
  • Patent Literature 1 does not refer to surface gloss; however, since recrystallization of the ferrite phase is progressed by sufficient soaking time, softening occurs and the steel sheet surface tends to be deformed. Thus, the above-described rolling-induced defects are generated, which results in a deterioration in surface gloss. In addition, in Patent Literature 1, since recrystallization is sufficiently progressed, surface irregularities cannot be prevented from generating in a cold rolling process with enough tension, which results in generation of roping.
  • Patent Literature 2 discloses a ferritic stainless steel sheet that is excellent in terms of ridging resistance, workability, and surface brightness and that is obtained by controlling the sheet-thickness-direction length of colonies to be 30% or less of the thickness of the sheet.
  • the method of controlling ferrite colonies in Patent Literature 2 does not reduce roping and the phenomenon of distortion of a reflected image on the surface visually observed still occurs.
  • Patent Literature 3 discloses a technique in which brightness is improved by decreasing the amount of oil drawn in order to reduce occurrence of oil pits and by minimizing the transfer of concave-convex patterns on the surfaces of rolls as a result of using hard low-surface-roughness work rolls in a cold rolling process.
  • the technique of Patent Literature 3 can remove rolling-induced surface defects, it cannot solve a problem of surface defects due to a raw material such as roping, ridging, and surface roughening.
  • An object of aspects of the present invention is, by solving the problems described above, to provide a material for a cold-rolled stainless steel sheet, the material being suitable for manufacturing a cold-rolled stainless steel sheet which is excellent in terms of surface appearance quality before and after a forming process and which has sufficient formability.
  • the term “excellent in terms of surface appearance quality before a forming process” refers to a case of being excellent in terms of surface brightness and roping resistance.
  • excellent in terms of surface brightness refers to a case where, when determining brightness of a test piece taken from the central portion in the width direction of a steel sheet at two points each in directions at angles of 0° and 90° to the rolling direction by using the reflected energy (Gs20°) of a light having an incidence angle of 20° in accordance with the prescription in JIS Z 8741, the average value of the determined values is 950 or more.
  • excellent in terms of roping resistance refers to a case where, when determining surface roughness in a direction at an angle of 90° to the rolling direction in accordance with JIS B 0601-2001, Rz is 0.2 ⁇ m or less.
  • the term “excellent in terms of surface appearance quality after a forming process” refers to a case of being excellent in terms of ridging resistance and surface roughening resistance.
  • excellent in terms of ridging resistance refers to a case where, after taking a JIS No.
  • excellent in terms of surface roughening resistance refers to a case where, when determining surface roughness in the polished surface in the middle of the parallel part of the test piece used for determining ridging resistance in accordance with JIS B 0601-2001, Ra is less than 0.2 ⁇ m.
  • the term “sufficient formability” refers to a case where, in a tensile test according to JIS Z 2241, a JIS No. 13B test piece taken in a direction perpendicular to the rolling direction exhibits an elongation after fracture (El) of 25% or more.
  • a stainless steel sheet is manufactured so as to have an appropriate composition and have a metallographic structure including a martensite phase having an area ratio of 5% to 50% and the balance being a ferrite phase, and is further controlled such that a ferrite phase in portions extending from the surface layers of the front and back surfaces of the steel sheet to, in the thickness direction of the sheet, positions at t/3 (t: thickness of the sheet), has an average grain diameter of 20 ⁇ m or more and 50 ⁇ m or less, and a ferrite phase in a central portion in the thickness direction of the sheet, the central portion being a portion of the sheet other than the portions extending from, in the thickness direction of the sheet, the surface layers to the positions at t/3 (t: thickness of the sheet), includes a ferrite phase satisfying an aspect ratio of more than 3.0.
  • % used when describing the chemical composition of steel shall always refer to mass %.
  • a material for a cold-rolled stainless steel sheet the material being suitable for manufacturing a cold-rolled stainless steel sheet which is excellent in terms of surface appearance quality before and after a forming process and which has sufficient formability.
  • a cold-rolled ferritic stainless steel sheet manufactured from a material for a cold-rolled stainless steel sheet according to aspects of the present invention is excellent in terms of surface appearance quality.
  • a material for a cold-rolled stainless steel sheet according to aspects of the present invention has a chemical composition containing C: 0.005% to 0.05%, Si: 0.02% to 0.75%, Mn: 0.1% to 1.0%, P: 0.04% or less, S: 0.01% or less, Cr: 16.0% to 18.0%, Al: 0.001% to 0.10%, N: 0.005% to 0.06%, and the balance being Fe and inevitable impurities, and a metallographic structure including a martensite phase having an area ratio of 5% to 50% and the balance being a ferrite phase, wherein a ferrite phase in portions extending from surface layers of front and back surfaces of a steel sheet to, in a thickness direction of the sheet, positions at t/3 (t: thickness of the sheet), has an average grain diameter of 20 ⁇ m or more and 50 ⁇ m or less, and a ferrite phase in a central portion in the thickness direction of the sheet, the central portion being a portion of the sheet other than the portions extending from, in the thickness direction
  • the amount of martensite phase and the conditions of the ferrite phase can be controlled by appropriately controlling coiling temperature in a hot rolling process, and by further performing, before a cold rolling process, hot-rolled-sheet annealing for a short time in a dual-phase temperature range in which a ferrite phase and an austenite phase are formed.
  • the coiling temperature is set to 550° C. to 850° C.
  • hot-rolled-sheet annealing is performed so as to hold the steel sheet at a temperature of 890° C. to 950° C. for 15 seconds to 2 minutes.
  • ferrite colonies aggregates of ferrite grains having similar crystal orientations
  • occurrence of ridging and roping which are caused by an increase of deformation capability in a specific orientation due to formation of the colonies.
  • the martensite phase not only achieves destruction of ferrite colonies before the cold rolling process and in the cold rolling process; also, in the cold-rolled-sheet annealing process, prior-austenite grain boundaries and block boundaries, lath boundaries, and the like within the martensite phase serve as recrystallization sites of a ferrite phase, which provides an effect of further destroying the colonies.
  • a ferrite phase in portions extending from the surface layers of the front and back surfaces of the steel sheet to positions at t/3 is controlled to have an average grain diameter of 20 ⁇ m or more and 50 ⁇ m or less, so that the surface layer portions after the cold-rolled-sheet annealing process have a metallographic structure that is a ferrite single-phase structure having small grain diameters.
  • the central portion in the thickness direction of the steel sheet includes a ferrite phase satisfying an aspect ratio of more than 3.0.
  • a ferrite phase satisfying an aspect ratio of more than 3.0 is unrecrystallized.
  • the material to be cold-rolled includes the unrecrystallized ferrite phase, it has a relatively hard metallographic structure, hence it becomes a hard material.
  • the effect of destroying ferrite colonies is obtained by forming a martensite phase by hot-rolled-sheet annealing.
  • the presence of the martensite phase after the hot-rolled-sheet annealing process provides the effect of further destroying ferrite colonies in the cold rolling process and after the cold-rolled-sheet annealing process, which contributes to inhibition of ridging and roping.
  • the martensite phase after the hot-rolled-sheet annealing process is controlled to have an area ratio of 5% to 50%, preferably 10% to 40%.
  • the area ratio of the austenite phase formed at the hot-rolled-sheet annealing temperature is nearly equal to the area ratio of the martensite phase after the hot-rolled-sheet annealing process.
  • This area ratio of the austenite phase depends on the steel composition and the hot-rolled-sheet annealing temperature. C, N, Mn, Ni, and Cu cause an increase in the area ratio of the martensite phase, while Si and Cr cause a decrease.
  • An increase in the annealing temperature causes an increase in the area ratio of the martensite phase, while a decrease in the annealing temperature causes a decrease.
  • a desired area ratio of the martensite phase can be obtained by controlling the composition and the hot-rolled-sheet annealing temperature.
  • the remainder is a ferrite phase.
  • the remainder may contain precipitates and inclusions. Examples of the precipitates and the inclusions are Cr carbonitride, V carbonitride, Ti carbonitride, Nb carbonitride, and alumina.
  • the total area ratio (area %) of the precipitates and the inclusions is preferably less than 5%.
  • Ferrite phase in portions extending from steel sheet surface layers of front and back surfaces of steel sheet to, in thickness direction of sheet, positions at t/3, has average grain diameter of 20 ⁇ m or more and 50 ⁇ m or less
  • Controlling the ferrite grain diameters of the surface layer portions is an important requirement for obtaining a desired surface appearance quality.
  • Controlling grain diameters before the cold rolling process provides a metallographic structure composed of fine ferrite grains after the cold rolling process and the cold-rolled-sheet annealing process, which enhances the effect of destroying ferrite colonies and also contributes to inhibition of surface roughening.
  • the material to be cold-rolled is controlled such that the ferrite phase has an average grain diameter of 50 ⁇ m or less.
  • the average grain diameter is more than 50 ⁇ m
  • ferrite grains which are recrystallized by starting from sites of coarse ferrite grains existed before the cold rolling process become coarse grains.
  • ferrite grains which are recrystallized by starting from the martensite phase become fine grains.
  • the final product has a mixed-grain microstructure of ferrite grains having different grain diameters, so that surface roughening occurs in a forming work process.
  • the average grain diameter is less than 20 ⁇ m, the steel sheet is excessively hardened.
  • the grain diameters of a ferrite phase in portions extending from the surface layers of the steel sheet to positions at t/3 in the thickness direction of the sheet are controlled such that the average grain diameter is 20 ⁇ m or more and 50 ⁇ m or less.
  • the portions extending from the surface layers to positions at t/3 in the thickness direction of the sheet where the grain diameters of the ferrite phase are controlled are a portion extending from the surface layer of the front surface of the steel sheet to the position at t/3 in the thickness direction of the sheet and a portion extending from the surface layer of the back surface of the steel sheet to the position at t/3 in the thickness direction of the sheet.
  • the remaining ferrite phase which is in a central portion in the thickness direction of the steel sheet, the central portion being a portion of the sheet other than the portions extending from the steel sheet surface layers of the front and back surfaces of the steel sheet to the positions at t/3, includes a ferrite phase satisfying an aspect ratio of more than 3.0.
  • the surface layer portions are composed of equiaxed grains, whereas the slab central portion is composed of considerably elongated grains due to a low cooling rate.
  • the ferrite phase in the surface layer portions is composed of finer equiaxed grains, because the ferrite phase present in the steel sheet surface layer portions in the hot rolling process is originally an equiaxed grains, and accumulation of strain caused by rolling and relax of the strain due to recrystallization are repeated during the hot rolling process.
  • the aspect ratio in accordance with aspects of the present invention is determined by the following formula (1).
  • r ⁇ (aspect ratio) d r (crystal grain diameter in the rolling direction)/ d t (crystal grain diameter in the thickness direction of the sheet) (1)
  • a hardness necessary and sufficient for decreasing the surface deformation capability without affecting the number of passes of cold rolling is obtained by including the ferrite phase satisfying an aspect ratio of more than 3.0.
  • the central portion in the thickness direction of the sheet is harder than the surface layers, deformation that occurs in the thickness direction of the sheet and in the width direction of the sheet under application of rolling tension is inhibited.
  • the entire portion in the thickness direction of the sheet is recrystallized and has a high deformation capability. Therefore, when rolling tension is applied, deformation in the thickness direction of the sheet and that in the width direction of the sheet vary in the width direction of the sheet, which results in occurrence of surface irregularities and unevenness.
  • the ratio of the ferrite phase satisfying an aspect ratio of more than 3.0 to the ferrite phase is preferably, in an area ratio, 10% or more.
  • the remaining ferrite phase of the central portion in the thickness direction of the sheet, the central portion being a portion of the sheet other than the portions extending from the sheet surface layers to the positions at t/3, may all be an unrecrystallized ferrite phase. More preferably, the ratio is, in an area ratio, 20% or more.
  • % refers to mass %, unless otherwise noted.
  • C provides an effect of promoting the formation of an austenite phase and expanding a dual-phase temperature range in which a ferrite phase and an austenite phase are formed in a hot-rolled-sheet annealing process.
  • C provides an effect of inhibiting an increase in grain diameter.
  • the amount of martensite formed is below the range according to aspects of the present invention, so that the specified brightness, roping resistance, ridging resistance, and surface roughening resistance cannot be achieved.
  • the C content is set to be 0.005% to 0.05%, preferably 0.01% to 0.03%, or more preferably 0.01% to 0.02%.
  • the term “C content” refers to the amount of C contained, and the same goes for other constituent chemical elements.
  • Si is a chemical element which functions as a deoxidizing agent in the process of preparing molten steel. In order to obtain such an effect, it is necessary that the Si content be 0.02% or more. However, in the case where the Si content is more than 0.75%, since there is an increase in the hardness of a steel sheet, there is an increase in rolling load in a hot rolling process and a deterioration in ductility after a finish annealing process.
  • the Si content is set to be 0.02% to 0.75%, preferably 0.10% to 0.50%, or more preferably 0.15% to 0.35%.
  • Mn provides, like C, an effect of promoting the formation of an austenite phase and expanding a dual-phase temperature range in which a ferrite phase and an austenite phase are formed in a hot-rolled-sheet annealing process.
  • the Mn content be 0.1% or more.
  • the Mn content is set to be 0.1% to 1.0%, preferably 0.55% to 0.90%, or more preferably 0.65% to 0.85%.
  • P is a chemical element which promotes intergranular fracturing due to intergranular segregation
  • the upper limit of the P content is set to be 0.04%, or preferably 0.03% or less.
  • S is a chemical element which deteriorates, for example, ductility and corrosion resistance as a result of existing in the form of sulfide-based inclusions such as MnS, and such negative harmful effects become marked, in particular, in the case where the S content is more than 0.01%. Therefore, it is desirable that the S content be as low as possible, and the upper limit of the S content is set to be 0.01%, preferably 0.007% or less, or more preferably 0.005% or less, in accordance with aspects of the present invention.
  • Cr is a chemical element which provides an effect of improving corrosion resistance by forming a passivation film on the surface of a steel sheet. This effect is obtained when the Cr content is 16.0% or more; and the higher the Cr content, the higher the corrosion resistance.
  • Cr provides an effect of inhibiting formation of an austenite phase in a hot-rolled-sheet annealing process. In the case where the Cr content is less than 16.0%, an excessively large amount of austenite phase is formed in a hot-rolled-sheet annealing process, so that the area ratio of the martensite phase cannot become 50% or less, which is specified in accordance with aspects of the present invention. Thus, the amount of martensite formed is beyond the range according to aspects of the present invention, so that the specified formability cannot be achieved.
  • the Cr content is set to be 16.0% or more.
  • the Cr content is set to be 18.0% or less, preferably 16.0% to 17.5%, or more preferably 16.5% to 17.0%.
  • Al is, like Si, a chemical element which functions as a deoxidizing agent. In order to obtain such an effect, it is necessary that the Al content be 0.001% or more. However, in the case where the Al content is more than 0.10%, since there is an increase in the amount of Al-based inclusions such as Al 2 O 3 , there is a tendency for surface quality to be deteriorated. Therefore, the Al content is set to be 0.001% to 0.10%, preferably 0.001% to 0.07%, or more preferably 0.001% to 0.01%.
  • N provides, like C and Mn, an effect of promoting the formation of an austenite phase and expanding a dual-phase temperature range in which a ferrite phase and an austenite phase are formed in a hot-rolled-sheet annealing process.
  • the N content be 0.005% or more.
  • the N content is set to be 0.005% to 0.06%, preferably 0.01% to 0.03%, or more preferably 0.01% to 0.02%.
  • the remainder is Fe and inevitable impurities.
  • Cu and Ni are both chemical elements which improve corrosion resistance. Containing Cu and/or Ni is effective, in particular, in the case where high corrosion resistance is required. In addition, Cu and Ni provide an effect of promoting the formation of an austenite phase and expanding a dual-phase temperature range in which a ferrite phase and an austenite phase are formed in a hot-rolled-sheet annealing process. Such effects become marked in the case where the content of each of these chemical elements is 0.1% or more. However, it is not preferable that the Cu content be more than 1.0%, because there may be a deterioration in hot workability. Therefore, in the case where Cu is contained, the Cu content is set to be 0.1% to 1.0%, preferably 0.2% to 0.8%, or more preferably 0.3% to 0.5%.
  • the Ni content be more than 1.0%, because there may be a deterioration in workability. Therefore, in the case where Ni is contained, the Ni content is set to be 0.1% to 1.0%, preferably 0.1% to 0.6%, or more preferably 0.1% to 0.3%.
  • Mo is a chemical element which improves corrosion resistance. Containing Mo is effective, in particular, in the case where high corrosion resistance is required. Such an effect becomes marked in the case where the Mo content is 0.1% or more. However, it is not preferable that the Mo content be more than 0.5%, because, since there is an insufficient amount of austenite phase formed in a hot-rolled-sheet annealing process, there is a case where it is not possible to achieve the specified surface appearance quality. Therefore, in the case where Mo is contained, the Mo content is set to be 0.1% to 0.5%, preferably 0.2% to 0.4%.
  • Co is a chemical element which improves toughness. Such an effect is obtained in the case where the Co content is 0.01% or more. On the other hand, in the case where the Co content is more than 0.3%, there may be a deterioration in manufacturability. Therefore, in the case where Co is added, the Co content is set to be 0.01% to 0.3%.
  • V 0.01% to 0.25%
  • Ti 0.001% to 0.015%
  • Nb 0.001% to 0.030%
  • Mg 0.0002% to 0.0050%
  • B 0.0002% to 0.0050%
  • REM 0.01% to 0.10%
  • V 0.01% to 0.25%
  • Ti 0.001% to 0.015%
  • Nb 0.001% to 0.030%
  • V, Ti, and Nb which are chemical elements having a high affinity for C and N, provide effects of improving workability after a finish annealing process by decreasing the amounts of a solid solute C and a solid solute N in a parent phase as a result of being precipitated in the form of carbides and nitrides in a hot rolling process.
  • the V content be 0.01% or more, or that the Ti content be 0.001% or more, or that the Nb content be 0.001% or more.
  • the V content is more than 0.25%, there may be a deterioration in workability.
  • the Ti content is more than 0.015% or where the Nb content is more than 0.030%
  • the V content is set to be 0.01% to 0.25%
  • the Ti content is set to be 0.001% to 0.015%
  • the Nb content is set to be 0.001% to 0.030%.
  • V content is preferably 0.02% to 0.20%, more preferably 0.03% to 10%.
  • Ti content is preferably 0.003% to 0.010%.
  • Nb content is preferably 0.002% to 0.020%, more preferably 0.003% to 0.015%.
  • Mg is a chemical element which has the effect of improving hot workability. In order to obtain this effect, it is necessary that the Mg content be 0.0002% or more. However, in the case where the Mg content is more than 0.0050%, there may be a deterioration in surface quality. Therefore, in the case where Mg is contained, the Mg content is set to be 0.0002% to 0.0050%, preferably 0.0005% to 0.0030%, or more preferably 0.0005% to 0.0010%.
  • the B is a chemical element which is effective for preventing secondary cold work embrittlement. In order to obtain such an effect, it is necessary that the B content be 0.0002% or more. However, in the case where the B content is more than 0.0050%, there may be a deterioration in hot workability. Therefore, in the case where B is contained, the B content is set to be 0.0002% to 0.0050%, preferably 0.0005% to 0.0030%, more preferably 0.0005% to 0.0010%.
  • REM is a chemical element which improves oxidation resistance and which provides, in particular, an effect of improving the corrosion resistance of a weld zone by inhibiting the formation of an oxide film in the weld zone.
  • the REM content be 0.01% or more.
  • the REM content is set to be 0.01% to 0.10%.
  • a steel material (slab) is obtained.
  • a hot-rolled steel sheet is obtained.
  • finish rolling is completed in the range of 900° C. to 1100° C.; subsequently, when the steel sheet is coiled, the coiling temperature is set to 550° C. to 850° C. More preferably, the coiling temperature is 600° C.
  • the austenite phase present in the hot rolling process is, substantially without being decomposed into a ferrite phase and carbonitride, cooled and transformed into martensite.
  • the martensite phase ratio is beyond the range according to aspects of the present invention, and the average grain diameter of the ferrite phase of the surface layer portions is below the range according to aspects of the present invention. Therefore, the specified formability and surface roughening resistance cannot be achieved.
  • the coiling temperature is more than 850° C., regardless of the amount of strain, recrystallization occurs and the amount of unrecrystallized ferrite phase in the central portion is considerably decreased, so that the specified glossiness cannot be achieved.
  • the coiling temperature is set to be 550° C. to 850° C. With this, it is possible to facilitate the control of grain diameter and recrystallization of a ferrite phase in a continuous hot-rolled-sheet annealing process which is completed in a short time.
  • the hot-rolled steel sheet is subjected to hot-rolled-sheet annealing in which the steel sheet is held at a temperature of 890° C. to 1050° C., that is, in a dual-phase temperature range in which a ferrite phase and an austenite phase are formed, for 10 seconds to 2 minutes.
  • the hot-rolled-sheet annealing temperature is less than 890° C.
  • the annealing is performed in the ferrite single-phase range, resulting in that the amount of martensite formed is below the range according to aspects of the present invention.
  • the effect of inhibiting occurrence of ridging and roping the effect being provided by formation of a martensite phase, cannot be provided.
  • the concentration of C in the austenite phase is promoted by progressing dissolution of carbides in solid, so that a large amount of excessively hard martensite phase is formed, resulting in a deterioration in elongation after the cold-rolled-sheet annealing process.
  • the amount of martensite formed is beyond the range according to aspects of the present invention, so that the specified formability cannot be achieved.
  • an increase in the size of ferrite grains is promoted and this is a cause of increasing the degree of surface roughening, which is not preferred.
  • the annealing time is less than 10 seconds
  • annealing at the specified temperature affects only the uppermost surfaces and recrystallization of the ferrite phase does not sufficiently progress in the thickness direction of the sheet. This results in a hard material to be cold-rolled, which increases the load of cold rolling.
  • the average grain diameter of the ferrite phase of the surface layer portions is below the range according to aspects of the present invention, so that the specified formability cannot be achieved.
  • the annealing time is more than 2 minutes, transformation into an austenite phase excessively progresses, so that the amount of martensite after cooling is more than a desired amount.
  • the surface layer portions in the thickness direction of the sheet are composed of excessively coarse ferrite grains.
  • the average grain diameter of the ferrite phase of the surface layer portions is beyond the range according to aspects of the present invention, so that the specified brightness and surface roughening resistance cannot be achieved.
  • recrystallization progresses to the center in the thickness direction of the sheet to cause softening.
  • the variation in hardness between the ferrite phase region and the martensite phase region causes fluctuations in the thickness of the sheet and fluctuations in the load in the cold rolling process, which causes a deterioration in the manufacturing capability.
  • a mixed-grain microstructure or a coarse ferrite single-phase structure is formed, resulting in a deterioration in surface roughening resistance.
  • pickling is performed as needed.
  • a cold-rolled ferritic stainless steel sheet is manufactured from the above-described material for a cold-rolled stainless steel sheet, it can be manufactured by the following method, for example.
  • the material for a cold-rolled steel sheet is subjected to cold rolling and cold-rolled-sheet annealing (finish annealing).
  • the cold rolling may be performed with any one of a tandem mill and a cluster mill.
  • the cold rolling is desirably performed at a rolling reduction of 50% or more from the viewpoint of formability and shape correction; however, this is not a limitation.
  • the cold-rolled-sheet annealing should be performed in a temperature range in which a ferrite single-phase is formed.
  • the annealing temperature range is set to 800° C. to 890° C., more preferably 850° C. to 890° C.
  • the temperature range is less than 800° C.
  • a martensite phase may remain and a deterioration in elongation may occur.
  • an austenite phase is newly formed and a martensite phase is formed in a cooling process, resulting in a significant deterioration in formability.
  • the cold-rolled-sheet annealing is desirably performed by a continuous annealing process, preferably a continuous annealing process of holding the cold-rolled sheet in a temperature range of 800° C. to 890° C. for 5 to 120 seconds.
  • the continuous annealing process is more preferably performed by holding the cold-rolled sheet for 10 to 60 seconds.
  • surface finish there is no particular limitation on surface finish, and appropriate surface finish may be selected from among, for example, No. 2B, BA, polishing, and dull finish.
  • skin pass rolling should be performed with an elongation ratio of 0.3% to 1.0%.
  • the stainless steels having the chemical compositions given in Table 1 were made into slabs having a thickness of 200 mm by using a continuous casting method. After having heated these slabs to a temperature of 1180° C., the slabs were subjected to hot rolling in which hot-rolled sheets were coiled at the temperatures given in Table 2, to thereby provide hot-rolled sheets having a thickness of 4 mm.
  • the hot-rolled and annealed steel sheets (materials for cold-rolled stainless steel sheets) were subjected to measurements in terms of the area ratio of the metallographic structure, ferrite grain diameter, and the ratio of an unrecrystallized ferrite phase by using the following methods.
  • an etched phase appearing black was identified as a martensite phase, and the other phase was separately identified as a ferrite phase.
  • Each field of view was subjected to image analysis to measure the area ratio of the martensite phase. And the average value of the area ratios in the 9 fields of view was determined as the area ratio of the martensite phase.
  • ferrite grain diameters were measured in accordance with JIS G 0551.
  • the average value of the diameters in the 6 fields of view was determined as the average grain diameter of the portions extending from the surface layers to the positions at t/3 (t: thickness of the sheet) in the thickness direction of the sheet.
  • ferrite grains were measured in terms of aspect ratio represented by the formula (1).
  • the area ratios of grains satisfying an aspect ratio of more than 3.0 were determined.
  • the average of the area ratios in the 3 fields of view was determined as the ratio of the unrecrystallized ferrite phase in the central portion in the thickness direction of the sheet, the central portion being a portion of the sheet other than the portions extending from the sheet surface layers to the positions at t/3.
  • cold-rolled stainless steel sheets were manufactured from the materials for cold-rolled stainless steel sheets by using the following method, and the properties of the cold-rolled stainless steel sheets were evaluated.
  • the hot-rolled and annealed steel sheets obtained above were cold-rolled to a thickness of 0.8 mm, and subjected to cold-rolled-sheet annealing under the conditions given in Table 2. After that, a descaling treatment was performed by electrolytic pickling. Finally, skin pass rolling was performed with an elongation ratio of 0.3% to 1.0%.
  • a JIS No. 13B tensile test piece was taken, from the central portion in the width direction of a steel sheet, in a direction at an angle of 90° to the rolling direction.
  • a tensile test was performed in accordance with JISZ 2241. A case where the elongation after fracture (El) was 25% or more was judged as satisfactory ( ⁇ ), and a case where the elongation after fracture (El) was less than 25% was judged as unsatisfactory ( ⁇ ). In addition, a case where the elongation after fracture (El) was 30% or more was judged as more than satisfactory ( ⁇ ).
  • a test piece was taken from the central portion in the width direction of the steel sheet, and then brightness was determined at two points each in directions at angles of 0° and 90° to the rolling direction by using the reflected energy (Gs20°) of a light having an incidence angle of 20° in accordance with the prescription in JIS Z 8741. Then, on the basis of the average value of the determined values, a case where the brightness was 950 or more was judged as a case of excellent brightness ( ⁇ ) and a case where the brightness was less than 950 was judged as unsatisfactory ( ⁇ ). In addition, a case where the brightness was more than 1000 was judged as more than excellent ( ⁇ ).
  • a test piece was taken from the central portion in the width direction of the steel sheet, and then surface roughness in a direction at an angle of 90° to the rolling direction was determined in accordance with JIS B 0601-2001. A case where Rz was 0.2 ⁇ m or less was judged as satisfactory ( ⁇ ) and a case where Rz was more than 0.2 ⁇ m was judged as unsatisfactory ( ⁇ ).
  • a JIS No. 5 test piece was taken, from the central portion in the width direction of the steel sheet, in a direction at an angle of 0° to the rolling direction; then one side of the test piece was polished to #600 finish, and a pre-strain of 20% was given to the test piece by applying a uniaxial tensile stress in accordance with JIS Z 2241. Then waviness height in the polished surface in the middle of the parallel part of the test piece was determined in accordance with JIS B 0601-2001. A case where the waviness height was 2.5 ⁇ m or less was judged as satisfactory ( ⁇ ) and a case where the waviness height was not 2.5 ⁇ m or less was judged as unsatisfactory ( ⁇ ). In addition, a case where the waviness height was less than 2.0 ⁇ m was judged as more than excellent ( ⁇ ).
  • the test piece having been used for determining ridging resistance was used.
  • Surface roughness in the polished surface in the middle of the parallel part of the test piece was determined in accordance with JIS B 0601-2001. A case where Ra was less than 0.2 ⁇ m was judged as satisfactory ( ⁇ ) and a case where Ra was not less than 0.2 ⁇ m was judged as unsatisfactory ( ⁇ ).
  • the material for a cold-rolled stainless steel sheet obtained by aspects of the present invention is suitably used as a material for a cold-rolled ferritic stainless steel sheet which are used for products manufactured by performing press forming involving mainly drawing and in applications in which high surface appearance quality is required such as kitchen equipment and eating utensils.

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JP6489254B2 (ja) * 2017-04-25 2019-03-27 Ｊｆｅスチール株式会社 ステンレス冷延鋼板用素材およびその製造方法
WO2018198835A1 (ja) * 2017-04-25 2018-11-01 Ｊｆｅスチール株式会社 ステンレス冷延鋼板用素材およびその製造方法
WO2020080015A1 (ja) * 2018-10-19 2020-04-23 Ｊｆｅスチール株式会社 フェライト系ステンレス鋼板およびその製造方法
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Citations (29)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS57155326A (en) 1981-03-23 1982-09-25 Nippon Steel Corp Production of ferritic stainless steel sheet excellent in workability
JPS6256529B2 (zh) 1979-09-04 1987-11-26 Abercom Africa Ltd
JPH04236717A (ja) 1991-01-21 1992-08-25 Sumitomo Metal Ind Ltd フェライト系ステンレス鋼板の製造方法
JPH09111354A (ja) 1995-10-13 1997-04-28 Sumitomo Metal Ind Ltd フェライト系ステンレス鋼板の製造方法
US5624504A (en) 1993-11-12 1997-04-29 Nisshin Steel Co., Ltd. Duplex structure stainless steel having high strength and elongation and a process for producing the steel
JPH1046293A (ja) 1996-07-26 1998-02-17 Nippon Steel Corp 延性とリジング性の優れたフェライト系ステンレス鋼板
JPH10330887A (ja) 1997-05-29 1998-12-15 Kawasaki Steel Corp 耐リジング性および加工性に優れた高光沢ステンレス鋼板およびその製造方法
JP2000102802A (ja) 1998-03-24 2000-04-11 Kawasaki Steel Corp 高光沢を有するステンレス冷延鋼帯の製造方法
JP2000265215A (ja) 1999-03-16 2000-09-26 Kawasaki Steel Corp 加工性の優れたフェライト系Ｃｒ含有鋼板の製造方法
JP2001098327A (ja) 1999-09-24 2001-04-10 Kawasaki Steel Corp 延性、加工性および耐リジング性に優れたフェライト系ステンレス鋼板の製造方法
JP2003293083A (ja) 2002-04-01 2003-10-15 Sumitomo Metal Ind Ltd 熱延鋼板並びに熱延鋼板及び冷延鋼板の製造方法
JP2004223536A (ja) 2003-01-21 2004-08-12 Nippon Steel Corp ローピング性に優れたフェライト系ステンレス鋼板の製造方法
EP1477574A2 (en) 2003-05-14 2004-11-17 JFE Steel Corporation High-strength stainless steel sheet and method for manufacturing the same
US6911098B2 (en) * 2001-10-31 2005-06-28 Jfe Steel Corporation Ferritic stainless steel sheet having excellent deep-drawability and brittle resistance to secondary processing and method for making the same
JP2006328524A (ja) 2005-01-24 2006-12-07 Nippon Steel & Sumikin Stainless Steel Corp 成形時の面内異方性が小さく耐リジング性及び耐肌荒れ性に優れたフェライト系ステンレス鋼薄板及びその製造方法
JP3922740B2 (ja) 1996-08-15 2007-05-30 新日本製鐵株式会社 表面特性及び耐食性の優れたフェライト系ステンレス鋼薄板の製造方法
JP2007197786A (ja) 2006-01-27 2007-08-09 Jfe Steel Kk 機械的性質とコンクリート中での耐食性に優れた鉄筋用Ｃｒ鋼
JP2008088534A (ja) 2006-10-05 2008-04-17 Jfe Steel Kk 冷延用フェライト系ステンレス熱延鋼板およびその製造方法
JP2008088535A (ja) 2006-10-05 2008-04-17 Jfe Steel Kk 冷延用フェライト系ステンレス熱延鋼板およびその製造方法
JP2009275268A (ja) 2008-05-16 2009-11-26 Jfe Steel Corp フェライト系ステンレス冷延鋼板およびその製造方法
JP2010001504A (ja) 2008-06-18 2010-01-07 Jfe Steel Corp ローピングと耳割れの発生を抑制できるステンレス冷延鋼板用素材およびその製造方法
JP2010047822A (ja) 2008-08-25 2010-03-04 Jfe Steel Corp 打抜き加工性に優れたステンレス冷延鋼板およびその製造方法
TW201202444A (en) 2010-03-29 2012-01-16 Nippon Steel & Amp Sumikin Stainless Steel Corp Dual phase structure stainless steel sheet and steel strip, and method for producing the dual phase structure stainless steel sheet and steel strip
US20130319583A1 (en) 2011-02-17 2013-12-05 Nippon Steel & Sumikin Stainless Steel Corporation High-purity ferritic stainless steel sheet with excellent oxidation resistance and high-temperature strength, and process for producing the same
WO2014103722A1 (ja) 2012-12-26 2014-07-03 新日鐵住金ステンレス株式会社 抗菌性に優れたフェライト系ステンレス鋼板及びその製造方法
US20140216614A1 (en) 2011-06-16 2014-08-07 Masaharu Hatano Ferritic stainless steel plate which has excellent ridging resistance and method of production of same
US20170275744A1 (en) 2014-09-05 2017-09-28 Jfe Steel Corporation Material for cold-rolled stainless steel sheet
US20170283923A1 (en) 2014-09-05 2017-10-05 Jfe Steel Corporation Cold-rolled ferritic stainless steel sheet
US10000824B2 (en) * 2014-01-24 2018-06-19 Jfe Steel Corporation Material for cold-rolled stainless steel sheet and production method therefor

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6256529A (ja) * 1985-09-06 1987-03-12 Nippon Steel Corp リジング特性の良好なフエライト系ステンレス鋼板の製造方法

Patent Citations (31)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6256529B2 (zh) 1979-09-04 1987-11-26 Abercom Africa Ltd
JPS57155326A (en) 1981-03-23 1982-09-25 Nippon Steel Corp Production of ferritic stainless steel sheet excellent in workability
JPH04236717A (ja) 1991-01-21 1992-08-25 Sumitomo Metal Ind Ltd フェライト系ステンレス鋼板の製造方法
US5624504A (en) 1993-11-12 1997-04-29 Nisshin Steel Co., Ltd. Duplex structure stainless steel having high strength and elongation and a process for producing the steel
JPH09111354A (ja) 1995-10-13 1997-04-28 Sumitomo Metal Ind Ltd フェライト系ステンレス鋼板の製造方法
JPH1046293A (ja) 1996-07-26 1998-02-17 Nippon Steel Corp 延性とリジング性の優れたフェライト系ステンレス鋼板
JP3922740B2 (ja) 1996-08-15 2007-05-30 新日本製鐵株式会社 表面特性及び耐食性の優れたフェライト系ステンレス鋼薄板の製造方法
JPH10330887A (ja) 1997-05-29 1998-12-15 Kawasaki Steel Corp 耐リジング性および加工性に優れた高光沢ステンレス鋼板およびその製造方法
JP2000102802A (ja) 1998-03-24 2000-04-11 Kawasaki Steel Corp 高光沢を有するステンレス冷延鋼帯の製造方法
JP2000265215A (ja) 1999-03-16 2000-09-26 Kawasaki Steel Corp 加工性の優れたフェライト系Ｃｒ含有鋼板の製造方法
JP2001098327A (ja) 1999-09-24 2001-04-10 Kawasaki Steel Corp 延性、加工性および耐リジング性に優れたフェライト系ステンレス鋼板の製造方法
US6911098B2 (en) * 2001-10-31 2005-06-28 Jfe Steel Corporation Ferritic stainless steel sheet having excellent deep-drawability and brittle resistance to secondary processing and method for making the same
JP2003293083A (ja) 2002-04-01 2003-10-15 Sumitomo Metal Ind Ltd 熱延鋼板並びに熱延鋼板及び冷延鋼板の製造方法
JP2004223536A (ja) 2003-01-21 2004-08-12 Nippon Steel Corp ローピング性に優れたフェライト系ステンレス鋼板の製造方法
EP1477574A2 (en) 2003-05-14 2004-11-17 JFE Steel Corporation High-strength stainless steel sheet and method for manufacturing the same
CN1550565A (zh) 2003-05-14 2004-12-01 ������������ʽ���� 高强度不锈钢板及其制造方法
JP2006328524A (ja) 2005-01-24 2006-12-07 Nippon Steel & Sumikin Stainless Steel Corp 成形時の面内異方性が小さく耐リジング性及び耐肌荒れ性に優れたフェライト系ステンレス鋼薄板及びその製造方法
JP2007197786A (ja) 2006-01-27 2007-08-09 Jfe Steel Kk 機械的性質とコンクリート中での耐食性に優れた鉄筋用Ｃｒ鋼
JP2008088534A (ja) 2006-10-05 2008-04-17 Jfe Steel Kk 冷延用フェライト系ステンレス熱延鋼板およびその製造方法
JP2008088535A (ja) 2006-10-05 2008-04-17 Jfe Steel Kk 冷延用フェライト系ステンレス熱延鋼板およびその製造方法
JP2009275268A (ja) 2008-05-16 2009-11-26 Jfe Steel Corp フェライト系ステンレス冷延鋼板およびその製造方法
JP2010001504A (ja) 2008-06-18 2010-01-07 Jfe Steel Corp ローピングと耳割れの発生を抑制できるステンレス冷延鋼板用素材およびその製造方法
JP2010047822A (ja) 2008-08-25 2010-03-04 Jfe Steel Corp 打抜き加工性に優れたステンレス冷延鋼板およびその製造方法
TW201202444A (en) 2010-03-29 2012-01-16 Nippon Steel & Amp Sumikin Stainless Steel Corp Dual phase structure stainless steel sheet and steel strip, and method for producing the dual phase structure stainless steel sheet and steel strip
EP2554702A1 (en) 2010-03-29 2013-02-06 Nippon Steel & Sumikin Stainless Steel Corporation Dual phase structure stainless steel sheet and steel strip, and method for producing the dual phase structure stainless steel sheet and steel strip
US20130319583A1 (en) 2011-02-17 2013-12-05 Nippon Steel & Sumikin Stainless Steel Corporation High-purity ferritic stainless steel sheet with excellent oxidation resistance and high-temperature strength, and process for producing the same
US20140216614A1 (en) 2011-06-16 2014-08-07 Masaharu Hatano Ferritic stainless steel plate which has excellent ridging resistance and method of production of same
WO2014103722A1 (ja) 2012-12-26 2014-07-03 新日鐵住金ステンレス株式会社 抗菌性に優れたフェライト系ステンレス鋼板及びその製造方法
US10000824B2 (en) * 2014-01-24 2018-06-19 Jfe Steel Corporation Material for cold-rolled stainless steel sheet and production method therefor
US20170275744A1 (en) 2014-09-05 2017-09-28 Jfe Steel Corporation Material for cold-rolled stainless steel sheet
US20170283923A1 (en) 2014-09-05 2017-10-05 Jfe Steel Corporation Cold-rolled ferritic stainless steel sheet

Non-Patent Citations (6)

* Cited by examiner, † Cited by third party
Title
Chinese Office Action for Chinese Application No. 201580047133.7, dated Jan. 17, 2018, including Concise Statement of Search Report, 7 pages.
Extended European Search Report for European Application No. 15837552.7, dated Jun. 12, 2017, 12 pages.
International Search Report and Written Opinion for International Application No. PCT/JP2015/003342, dated Sep. 15, 2015 6 Pages.
Korean Office Action for Korean Application No. 10-2017-7006038, dated Jun. 21, 2018, with Concise Statement of Relevance of Office Action, 5 pages.
Non Final Office Action for U.S. Appl. No. 15/112,901, dated Nov. 3, 2017, 8 pages.
Taiwan Office Action for Taiwan Application No. 104122006, dated Mar. 1, 2016 with Concise Statement of Relevance of Office Action, 4 pages.

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